The explosive growth of digital photography has surprised not only laymen, but also some people involved in its development.

There was recent news that one of the world’s weirdest and most groundbreaking camera systems, Lytro, had become even weirder and more groundbreaking thanks to the addition of new software effects.

The Lytro captures an “image field” – with not just the colours and intensity typical of cameras, but also the directions light rays are travelling. This made it possible to view an image on screen and choose which part snaps into focus. As if this wasn’t weird enough, you can now also use a mouse to wiggle the contents of an image around as if moving your head left, right, up and down while viewing an actual scene.

By capturing images that till recently were only possible with experimenters’ arrays of perhaps a hundred cameras, the Lytro is almost the stuff of science fiction. But for something else that would have seemed astonishing just a few years ago, consider how many of us have a pocket-sized smartphone equipped with a multi-megapixel camera.

The explosive growth of digital photography has surprised not only laymen, but also some people involved in its development. Steve Sasson, a Kodak engineer credited with creating the world’s first digital camera in 1975, has reported that he and his colleagues were only looking at it as akin to proof of concept, with real world application a distant possibility.

Kodak was then a major company, which had achieved early success through introducing a film camera costing one US dollar in 1900. Film was a core business, and Sasson did not enthuse managers by giving internal presentations titled “Film-less photography”.

That first camera adopted some of the technology that NASA had developed for transmitting images from the moon. During the 1960s, NASA engineers worked on the idea of using mosaics of photosensors to create digital images, and one of them coined the term “pixel” as shorthand for picture element.

CCDs – charge coupled devices – were the main kinds of early sensors, and are still in use today. Each is made from layers including semiconductor and metal oxide. When a pixel is hit by photons, electrons are released, and their charge is later transferred from the sensor, resulting in voltage used for building the digital image. Light from across the spectrum can release electrons, and arrays of filters are typically used to create colour images, ensuring each pixel responds only to red, green or blue.

Kodak was confused by the new technology. On the one hand, it poured over US$4 billion into developing digital photography, and in 1991 released the world’s first professional digital camera. Yet in a salutary lesson of how not to respond to disruptive technologies, the company was also loathe to push products that might harm its film sales. After sowing the seeds of its own demise, Kodak lost market share to nimbler companies, and filed for bankruptcy early last year. Even so, Kodak-branded cameras may reappear, made by somewhat mysterious start up JK Imaging.

With digital photography now so prevalent, it may be surprising to reflect that National Geographic’s first feature shot wholly on digital cameras appeared in 2003, and it was not until 2005 that Kodak’s digital sales exceeded film sales.

The surge in digital photography was spurred partly by the emergence of CMOS (complementary metal oxide semiconductor) sensors. These are cheaper to mass produce and require less power than CCD sensors, and in the early 1990s NASA devised active circuitry that boosted their signal while reducing noise.

Cameras with CMOS sensors now abound, including in smartphones. Samsung estimates at least 2.5 billion people – over a third of the world population – own a digital camera. And soon, you may be able to buy a smartphone packing abilities akin to a Lytro camera, thanks to a new light field CMOS sensor from Toshiba.

But while CMOS rules here on Planet Earth, if you look up at the night sky you might see a planet where its sibling is number one: Mars. For as you read, this, on a planet far, far away, the Curiosity rover is recording scenes using three CCD sensors.

Digital photography is not only groundbreaking. It’s out of this world.